classes/plsqljoin.php

   1 <?php
   2 /***************************************************************************
   3  *  Copyright (C) 2003-2010 Polytechnique.org                              *
   4  *  http://opensource.polytechnique.org/                                   *
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   7  *  it under the terms of the GNU General Public License as published by   *
   8  *  the Free Software Foundation; either version 2 of the License, or      *
   9  *  (at your option) any later version.                                    *
  10  *                                                                         *
  11  *  This program is distributed in the hope that it will be useful,        *
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of         *
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          *
  14  *  GNU General Public License for more details.                           *
  15  *                                                                         *
  16  *  You should have received a copy of the GNU General Public License      *
  17  *  along with this program; if not, write to the Free Software            *
  18  *  Foundation, Inc.,                                                      *
  19  *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA                *
  20  ***************************************************************************/
  21
  22 // {{{ class PlSqlJoin
  23 class PlSqlJoin
  24 {
  25     private $mode;
  26     private $table;
  27     private $condition;
  28
  29     const MODE_LEFT  = 'LEFT';
  30     const MODE_RIGHT = 'RIGHT';
  31     const MODE_INNER = 'INNER';
  32
  33     private function __construct($mode, $params)
  34     {
  35         $table = array_shift($params);
  36         $condition = XDB::prepare($params);
  37         if ($mode != self::MODE_LEFT && $mode != self::MODE_RIGHT && $mode != self::MODE_INNER) {
  38             Platal::page()->kill("Join mode error: unknown mode $mode");
  39             return;
  40         }
  41         $this->mode = $mode;
  42         $this->table = $table;
  43         $this->condition = $condition;
  44     }
  45
  46     public function mode()
  47     {
  48         return $this->mode;
  49     }
  50
  51     public function table()
  52     {
  53         return $this->table;
  54     }
  55
  56     public function condition()
  57     {
  58         return $this->condition;
  59     }
  60
  61     /** Replace all "metas" in the condition with their translation.
  62      * $ME always becomes the alias of the table
  63      * @param $key The name the joined table will have in the final query
  64      * @param $joinMetas An array of meta => conversion to apply to the condition
  65      */
  66     public function replaceJoinMetas($key, $joinMetas = array())
  67     {
  68         $joinMetas['$ME'] = $key;
  69         return str_replace(array_keys($joinMetas), $joinMetas, $this->condition);
  70     }
  71
  72     /** Create a join command from an array of PlSqlJoin
  73      * @param $joins The list of 'join' to convert into an SQL query
  74      * @param $joinMetas An array of ('$META' => 'conversion') to apply to the joins.
  75      */
  76     public static function formatJoins(array $joins, array $joinMetas)
  77     {
  78         $str = '';
  79         foreach ($joins as $key => $join) {
  80             if (!($join instanceof PlSqlJoin)) {
  81                 Platal::page()->kill("Error: not a join: $join");
  82             }
  83             $mode  = $join->mode();
  84             $table = $join->table();
  85             $str .= ' ' . $mode . ' JOIN ' . $table . ' AS ' . $key;
  86             if ($join->condition() != null) {
  87                 $str .= ' ON (' . $join->replaceJoinMetas($key, $joinMetas) . ')';
  88             }
  89             $str .= "\n";
  90         }
  91         return $str;
  92     }
  93
  94     /** Build a left join
  95      * @param table The name of the table.
  96      * @param condition The condition of the jointure
  97      */
  98     public static function left()
  99     {
 100         $params = func_get_args();
 101         return new PlSqlJoin(self::MODE_LEFT, $params);
 102     }
 103
 104     /** Build a right join
 105      * @param table The name of the table.
 106      * @param condition The condition of the jointure
 107      */
 108     public static function right()
 109     {
 110         $params = func_get_args();
 111         return new PlSqlJoin(self::MODE_RIGHT, $params);
 112     }
 113
 114     /** Build a inner join
 115      * @param table The name of the table.
 116      * @param condition The condition of the jointure
 117      */
 118     public static function inner()
 119     {
 120         $params = func_get_args();
 121         return new PlSqlJoin(self::MODE_INNER, $params);
 122     }
 123 }
 124 // }}}
 125
 126 // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8:
 127 ?>